Gas turbine plant

ABSTRACT

A gas turbine plant comprises an air compressor, gas turbine including at least one high temperature section, a driven equipment, which are operatively connected in series, a gas turbine combustor arranged between the air compressor and the gas turbine, a fuel system disposed for supplying a fuel to the gas turbine combustor, and a heat exchange section for heating the fuel from the fuel by means of a high pressure air as a heating medium fed from the air compressor.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a gas turbine plant, and inparticular, to a gas turbine plant which previously heats a fuelsupplied to a gas turbine combustor of the gas turbine plant andenhances a quantity of heat so as to improve a plant heat (thermal)efficiency.

[0002] In a gas turbine plant, it has been known that the plant heatefficiency is improves if an inlet combustion temperature of a gasturbine is made high. The plant heat efficiency is calculated from aratio of a gas turbine power to a fuel supplied to a gas turbinecombustor.

[0003] Therefore, how to reduce a fuel to be supplied to the gas turbinecombustor, or how to enhance an output of the gas turbine is animportant matter in order to improve the plant heat efficiency.

[0004] In view of the gas turbine output power in the light of theimprovement of the plant heat efficiency, there is a problem of anincrease in a power per unit combustion gas flow (specific power).However, an improvement of flow characteristic of a gas turbine bladeand a reduction in other mechanical loss have already reached the limit,and it is difficult to greatly improve the flow characteristic andreduce the mechanical loss.

[0005] On the other hand, in order to reduce fuel consumption so as toimprove the plant heat efficiency, it is important to improve a quantityof heat of fuel itself.

[0006] Recently, there has been disclosed Japanese Patent No. 2540646 asmeans for improving the quantity of heat of fuel itself. As shown inFIG. 29, the Japanese Patent No. 2540646 relates to a so-calledmulti-shaft type combined cycle power generation plant which isconstructed in such a manner that a shaft of a gas turbine plant 2connected to an exhaust heat recovery boiler 1 is separated, and a steamturbine plant 3 is independently provided. A gas turbine combustor 4 isprovided with a heat exchanger 5, and a heated water generated from aneconomizer 6 of the exhaust heat recovery boiler 1 is used as a heatingsource to be supplied to the heat exchanger 5, and thus, a heat exchangeof a fuel F supplied to the gas turbine combustor 4 is made to increasea quantity of heat.

[0007] As described above, in the Japanese Patent No. 2540646, effortshave been made to reduce fuel consumption and to improve a plant heatefficiency because there is an anxiety that fossil fuel resources areexhausted in near future.

[0008] In the prior art shown in FIG. 29, a heated water on an outletside of the economizer 6 having a relatively small influence on loadfluctuation is used as a heating source of the heat exchanger 5 so as toheat the fuel F, and then, a gas turbine driving gas (main flow gas)having the same temperature is generated by a fuel flow rate relativelysmaller that that of the conventional case, and thus, a plant heatefficiency is improved. However, the heated water on the outlet side ofthe economizer 6 has been used as a heating source of the fuel F, andfor this reason, there have arisen several problems.

[0009] Primarily, the temperature of heated water generated from theeconomizer 6 is set on the basis of heat balance of the whole plantregardless of heating the fuel F. For this reason, the temperature ofthe heated water becomes high by heating the fuel, and then, asaturation pressure based on the high temperature of heated waterexcessively becomes high. Thus, a feed water pump 6 a requires a highpressure rising force, and thus, this is a factor of increasing thecost.

[0010] During partial load operation, when a flow rate of the heat watersupplied to the heat exchanger 5 becomes low, a quantity of feed waterfrom the feed water pump 6 a passing through the economizer 6 becomeslow. In this case, however, an internal pressure of the feed water pumprises, and for this reason, the heat water discharged from theeconomizer 6 exceeds a saturation temperature. As a result, there is thepossibility that steaming is generated.

[0011] Further, the heated water of the economizer 6 is used as aheating source of the fuel F. In this case, however, the aforesaidconstruction is applied to only the combined cycle power generationplant. For example, in the case of a simple cycle gas turbine, it isdifficult to secure a heating source, and for this reason, there hasbeen required a gas turbine plant which can readily secure the heatingsource.

[0012] As described above, the prior art shown in FIG. 29 can improvethe plant heat efficiency, but provides the aforesaid several problems.

SUMMARY OF THE INVENTION

[0013] A primary object of the present invention is to substantiallyeliminate defects or drawbacks encountered in the prior art describedabove and to provide a gas turbine plant capable of relatively reducinga flow rate of fuel so as to improve a plant heat efficiency withoutgiving any influence to other constituent equipments when using the gasturbine plant itself as a heating source for heating a fuel.

[0014] This and other objects can be achieved according to the presentinvention by providing, in one aspect, a gas turbine plant comprising:

[0015] an air compressor;

[0016] a gas turbine;

[0017] a driven equipment, the air compressor, the gas turbine and thedriven equipment being operatively connected in series;

[0018] a gas turbine combustor arranged between the air compressor andthe gas turbine;

[0019] a fuel system for supplying a fuel to the gas turbine combustor;and

[0020] a heat exchange section for heating the fuel from the fuel systemby means of a high pressure air as a heating source from the aircompressor.

[0021] In a preferred embodiment, the heat exchange section is housed inthe air compressor or mounted to a casing of the air compressor, and inthe case of mounting to the casing, a fuel passage is formed by an outercover covering an outer periphery of the casing, one side of the fuelpassage being provided with a fuel inlet and a fuel outlet and anotherside of the fuel passage is provided with a connecting pipe.

[0022] In another aspect, there is provided a gas turbine plantcomprising:

[0023] an air compressor;

[0024] a gas turbine;

[0025] a driven equipment, the air compressor, the gas turbine and thedriven equipment being operatively connected in series;

[0026] a gas turbine combustor arranged between the air compressor andthe gas turbine;

[0027] a fuel system for supplying a fuel to the gas turbine combustor;

[0028] an extraction closed circuit system provided for the aircompressor; and

[0029] a heat exchange section provided for the extraction closedcircuit system for heating the fuel supplied to the gas turbinecombustor from the fuel system.

[0030] In a further aspect, there is provided a gas turbine plantcomprising:

[0031] an air compressor;

[0032] a gas turbine including an exhaust gas system;

[0033] a driven equipment, the air compressor, the gas turbine and thedriven equipment being operatively connected in series;

[0034] a gas turbine combustor arranged between the air compressor andthe gas turbine;

[0035] a fuel system for supplying a fuel to the gas turbine combustor;and

[0036] a heat exchange section provided for the exhaust gas system ofthe gas turbine for heating the fuel supplied to the gas turbinecombustor from the fuel system.

[0037] In a still further aspect, there is provided a gas turbine plantcomprising:

[0038] an air compressor;

[0039] a gas turbine including a high temperature section;

[0040] a driven equipment, the air compressor, the gas turbine and thedriven equipment being operatively connected in series;

[0041] a gas turbine combustor arranged between the air compressor andthe gas turbine;

[0042] a fuel system for supplying a fuel to the gas turbine combustor;

[0043] a high pressure air supply system operatively connected to thehigh temperature section of the gas turbine for supplying a highpressure air from the air compressor thereto;

[0044] a heat exchange section provided for the high pressure air supplysystem for heating the fuel supplied to the gas turbine combustor fromthe fuel system, the high pressure air after the heating being suppliedto the high temperature section of the gas turbine as a cooling medium;and

[0045] a high pressure air recovery system for recovering the an overallquantity or part of the high pressure air to the air compressor aftercooling the high temperature section of the gas turbine.

[0046] In this aspect, the high pressure air supply system is dividedinto a plurality of high pressure air supply sections in accordance witha magnitude of pressure loss of the high pressure air passing throughthe high temperature section of the gas turbine, the plurality of highpressure air supply sections each being provided with a flowdistributing device. The flow distributing device is either one of aflow control valve and an orifice. The high pressure air recovery systemis divided into a plurality of high pressure air recovery sections so asto correspond to the divided plurality of high pressure air supplysections.

[0047] In a still further aspect, there is provided a gas turbine plantcomprising:

[0048] an air compressor;

[0049] a gas turbine including a high temperature section;

[0050] a driven equipment, the air compressor, the gas turbine and thedriven equipment being operatively connected in series;

[0051] a gas turbine combustor arranged between the air compressor andthe gas turbine;

[0052] a fuel system for supplying a fuel to the gas turbine combustor;

[0053] a high pressure air supply system operatively connected to thehigh temperature section of the gas turbine for supplying a highpressure air from the air compressor thereto; and

[0054] a heat exchange section provided for the high pressure air supplysystem for heating the fuel supplied to the gas turbine combustor fromthe fuel system, the high pressure air after the heating being suppliedto the high temperature section of the gas turbine as a cooling mediumand the high pressure air after cooling the high temperature sectionbeing joined with a gas turbine driving gas.

[0055] In a still further aspect, there is provided a gas turbine plantcomprising:

[0056] an air compressor;

[0057] a gas turbine including at least one high temperature section;

[0058] a driven equipment, the air compressor, the gas turbine and thedriven equipment being operatively connected in series;

[0059] a gas turbine combustor arranged between the air compressor andthe gas turbine;

[0060] a fuel system for supplying a fuel to the gas turbine combustor;

[0061] a high pressure air supply system operatively connected to thehigh temperature section of the gas turbine for supplying a highpressure air from the air compressor thereto;

[0062] a heat exchange section provided for the high pressure air supplysystem for heating the fuel supplied to the gas turbine combustor fromthe fuel system;

[0063] a pressure rising compressor for rising a pressure of the highpressure air after heating the fuel and for supplying the high pressureair to at least one of the high temperature sections of the gas turbineas a cooling medium; and

[0064] at least one high pressure air recovery system for recovering anoverall quantity or part of the high pressure air after cooling the atleast one of the high temperature sections of the gas turbine to the aircompressor.

[0065] In a still further aspect, there is provided a gas turbine plantcomprising:

[0066] an air compressor;

[0067] a gas turbine including at least one high temperature section;

[0068] a driven equipment, the air compressor, the gas turbine and thedriven equipment being operatively connected in series;

[0069] a gas turbine combustor arranged between the air compressor andthe gas turbine;

[0070] a fuel system for supplying a fuel to the gas turbine combustor;

[0071] a high pressure air supply system operatively connected to thehigh temperature section of the gas turbine for supplying a highpressure air from the air compressor thereto;

[0072] a beat exchange section provided for the high pressure air supplysystem for heating the fuel supplied to the gas turbine combustor fromthe fuel system;

[0073] a first pressure rising compressor for rising a pressure of thehigh pressure air after heating the fuel and for supplying the highpressure air to at least one of the high temperature sections of the gasturbine as a cooling medium;

[0074] a second pressure rising compressor which is bypassed from anoutlet side of the first pressure rising compressor and rising apressure of the high pressure air after heating the fuel and forsupplying the high pressure air to at least one of other hightemperature sections of the gas turbine as a cooling medium; and

[0075] a high pressure air recovery system for recovering an overallquantity or part of the high pressure air after cooling the hightemperature sections of the gas turbine to the air compressor.

[0076] In a still further aspect, there is provided a gas turbine plantcomprising:

[0077] an air compressor;

[0078] a gas turbine including a plurality of high temperature sections;

[0079] a driven equipment, the air compressor, the gas turbine and thedriven equipment being operatively connected in series;

[0080] a gas turbine combustor arranged between the air compressor andthe gas turbine;

[0081] a fuel system for supplying a fuel to the gas turbine combustor;

[0082] a high pressure air supply system operatively connected to thehigh temperature sections of the gas turbine for supplying a highpressure air from the air compressor thereto;

[0083] a heat exchange section provided for the high pressure air supplysystem for heating the fuel supplied to the gas turbine combustor fromthe fuel system;

[0084] a plurality of pressure rising compressors for rising a pressureof the high pressure air after heating the fuel and for supplying thehigh pressure air to the high temperature sections, respectively, as acooling medium; and

[0085] a high pressure air recovery system for recovering an overallquantity or part of the high pressure air after cooling the the hightemperature sections of the gas turbine to the air compressor.

[0086] In a still further aspect, there is provided a gas turbine plantcomprising:

[0087] an air compressor;

[0088] a gas turbine including a plurality of high temperature sections;

[0089] a driven equipment, the air compressor, the gas turbine and thedriven equipment being operatively connected in series;

[0090] a gas turbine combustor arranged between the air compressor andthe gas turbine;

[0091] a fuel system for supplying a fuel to the gas turbine combustor;

[0092] a high pressure air supply system operatively connected to thehigh temperature sections of the gas turbine for supplying a highpressure air from the air compressor thereto;

[0093] a heat exchange section provided for the high pressure air supplysystem for heating the fuel supplied to the gas turbine combustor fromthe fuel system;

[0094] a pressure rising compressor for rising a pressure of the highpressure air after heating the fuel and for supplying the high pressureair to the at least one high temperature section as a cooling medium,said high pressure air supply system being directly connected to atleast one of other high temperature sections so as to supply the highpressure air after heating the fuel as a cooling medium; and

[0095] a plurality of high pressure air recovery systems for recoveringan overall quantity or part of the high pressure air after cooling thehigh temperature sections of the gas turbine to the air compressor inaccordance with the plurality of high temperature sections,respectively.

[0096] In a still further aspect, there is provided a gas turbine plantcomprising:

[0097] an air compressor;

[0098] a gas turbine including a plurality of high temperature sections;

[0099] a driven equipment, the air compressor, the gas turbine and thedriven equipment being operatively connected in series;

[0100] a gas turbine combustor arranged between the air compressor andthe gas turbine;

[0101] a fuel system for supplying a fuel to the gas turbine combustor;

[0102] a high pressure air supply system operatively connected to thehigh temperature sections of the gas turbine for supplying a highpressure air from the air compressor thereto;

[0103] a heat exchange section provided for the high pressure air supplysystem for heating the fuel supplied to the gas turbine combustor fromthe fuel system;

[0104] a pressure rising compressor for rising a pressure of the highpressure air after heating the fuel and for supplying the high pressureair to the high temperature sections of the gas turbine as a coolingmedium;

[0105] a high pressure air recovery system for recovering an overallquantity or part of the high pressure air after cooling at least one ofsaid high temperature sections of the gas turbine to the air compressor;and

[0106] a cooling recovery system for recovering the overall quantity orpart of the high pressure air after cooling at least one of other hightemperature sections of the gas turbine to an inlet side of the heatexchange section.

[0107] In a still further aspect, there is provided a gas turbine plantcomprising:

[0108] an air compressor;

[0109] a gas turbine including a high temperature section;

[0110] a driven equipment, the air compressor, the gas turbine and thedriven equipment being operatively connected in series;

[0111] a gas turbine combustor arranged between the air compressor andthe gas turbine;

[0112] a fuel system for supplying a fuel to the gas turbine combustor;and

[0113] a high pressure air supply system operatively connected to thehigh temperature section of the gas turbine for supplying the highpressure air from the air compressor, the high pressure air supplysystem being provided with a heat exchange section for heating the fuelfrom the fuel system and another heat exchange section for heating aheat utilizing device for heating a medium to be heated of the heatutilizing device.

[0114] In a still further aspect, there is provided a gas turbine plantcomprising:

[0115] an air compressor;

[0116] a gas turbine including a high temperature section;

[0117] a driven equipment, the air compressor, the gas turbine and thedriven equipment being operatively connected in series;

[0118] a gas turbine combustor arranged between the air compressor andthe gas turbine;

[0119] a fuel system for supplying a fuel to the gas turbine combustor;and

[0120] an air extraction closed circuit system provided for the aircompressor, the air extraction closed circuit system being provided witha heat exchange section for heating the fuel from said fuel system andanother heat exchange section for heating a heat utilizing device forheating a medium to be heated of the heat utilizing device.

[0121] In a still further aspect, there is provided a gas turbine plantcomprising:

[0122] an air compressor;

[0123] a gas turbine including an exhaust gas system and being combinedwith a steam turbine;

[0124] a driven equipment, the air compressor, the gas turbine and thedriven equipment being operatively connected in series;

[0125] a gas turbine combustor arranged between the air compressor andthe gas turbine;

[0126] a fuel system for supplying a fuel to the gas turbine combustor;

[0127] a heat exchange section provided for the exhaust gas system ofthe gas turbine for heating a fuel supplied from the fuel system to thegas turbine combustor; and

[0128] a plurality of exhaust heat recovery heat exchange sectionprovided for the exhaust gas system of the gas turbine for heating afeed water of the steam turbine plant so as to generate a steam.

[0129] In a still further aspect, there is provided a gas turbine plantcomprising:

[0130] an air compressor;

[0131] a gas turbine including a high temperature section;

[0132] a driven equipment, the air compressor, the gas turbine and thedriven equipment being operatively connected in series;

[0133] a gas turbine combustor arranged between the air compressor andthe gas turbine;

[0134] a fuel system for supplying a fuel to the gas turbine combustor;and

[0135] an air extraction closed circuit system provided for the aircompressor, the air extraction closed circuit system being provided witha heat exchange section for heating the fuel from the fuel system to thegas turbine combustor, a valve opening control unit for detecting a fuelleak into the high pressure air by a fuel leak detector provided for theheat exchange section and for closing a fuel valve of the fuel systemwhen a detection signal exceeds a predetermined value, and an alarmdevice for giving an alarm when the detection signal exceeds thepredetermined value.

[0136] In a still further aspect, there is provided a gas turbine plaintcomprising:

[0137] an air compressor;

[0138] a gas turbine;

[0139] a driven equipment, the air compressor, the gas turbine and thedriven equipment being operatively connected in series;

[0140] a gas turbine combustor arranged between the air compressor andthe gas turbine;

[0141] a fuel system for supplying a fuel to the gas turbine combustor;and

[0142] a heat exchange section for heating the fuel from the fuel systemby means of a high pressure air as a heating source from the aircompressor, the heat exchange section being divided into a first heatexchange unit for heating an intermediate heating medium by a hightemperature heating medium and a second heat exchange unit for heatingthe fuel by the thus heated intermediate heating medium.

[0143] In a still further aspect, there is provided a gas turbine plantcomprising:

[0144] an air compressor;

[0145] a gas turbine;

[0146] a driven equipment, the air compressor, the gas turbine and thedriven equipment being operatively connected in series;

[0147] a gas turbine combustor arranged between the air compressor andthe gas turbine;

[0148] a fuel system for supplying a fuel to the gas turbine combustor;and

[0149] a heat exchange section for heating the fuel from the fuel systemby means of a high pressure air as a heating source from the aircompressor, the heat exchange section being divided into a hightemperature chamber and a low temperature chamber and being providedwith a heating pipe crossing the high temperature chamber and the lowtemperature chamber so that the heating pipe is heated by a hightemperature heating medium in the high temperature chamber and the fuelis heated in the low temperature chamber.

[0150] In a still further aspect, there is provided a gas turbine plantcomprising:

[0151] an air compressor including an air discharging unit;

[0152] a gas turbine;

[0153] a driven equipment, the air compressor, the gas turbine and thedriven equipment being operatively connected in series;

[0154] a gas turbine combustor arranged between the air compressor andthe gas turbine;

[0155] a fuel system for supplying a fuel to the gas turbine combustor;

[0156] a discharge air recovery system provided so as to bypass the airdischarging system of the air compressor, the air discharging unit beingprovided with an air discharge valve to which is disposed a valveopening control unit which opens and closes the air discharge valve inresponse to at least one signal of a rotational speed signal of a gasturbine shaft and a power signal of the driven equipment; and

[0157] a heat exchange section provided for the discharge air recoverysystem for heating the fuel supplied from the fuel system to the gasturbine combustor.

[0158] In a still further aspect, there is provided a gas turbine plantcomprising:

[0159] an air compressor;

[0160] a gas turbine including at least one high temperature section;

[0161] a driven equipment, the air compressor, the gas turbine and thedriven equipment being operatively connected in series;

[0162] a gas turbine combustor arranged between the air compressor andthe gas turbine;

[0163] a fuel system for supplying a fuel to the gas turbine combustor;

[0164] a high pressure air supply system operatively connected to thehigh temperature section of the gas turbine for supplying a highpressure air from the air compressor thereto;

[0165] a heat exchange section provided for the high pressure air supplysystem for heating the fuel supplied to the gas turbine combustor fromthe fuel system;

[0166] a pressure rising compressor for rising a pressure of the highpressure air after heating the fuel and for supplying the high pressureair to at least one of the high temperature sections of the gas turbineas a cooling medium, said pressure rising compressor being connected toa gas turbine shaft; and

[0167] at least one high pressure air recovery system for recovering anoverall quantity or part of the high pressure air after cooling the atleast one of the high temperature sections of the gas turbine to the aircompressor.

[0168] In this aspect, the pressure rising compressor is directlyconnected to the gas turbine shaft or connected through a powertransmission mechanism, which may be composed of either one of a gearmechanism and a torque converter mechanism.

[0169] In a still further aspect, there is provided a gas turbine plantcomprising:

[0170] an air compressor;

[0171] a gas turbine including at least one high temperature section;

[0172] a driven equipment, the air compressor, the gas turbine and thedriven equipment being operatively connected in series;

[0173] a gas turbine combustor arranged between the air compressor andthe gas turbine;

[0174] a fuel system for supplying a fuel to the gas turbine combustor;

[0175] a high pressure air supply system operatively connected to thehigh temperature section of the gas turbine for supplying a highpressure air from the air compressor thereto;

[0176] a heat exchange section provided for the high pressure air supplysystem for heating the fuel supplied to the gas turbine combustor fromthe fuel system;

[0177] a pressure rising compressor for rising a pressure of the highpressure air after heating the fuel and for supplying the high pressureair to at least one of the high temperature sections of the gas turbineas a cooling medium;

[0178] a re-circulation system bypassing from an intermediate portionbetween an outlet side of the pressure rising compressor and a checkvalve disposed to an inlet side of the high temperature section of thegas turbine, the re-circulation system being provided with are-circulation valve and being connected to an inlet side of the heatexchange section; and

[0179] at least one high pressure air recovery system for recovering anoverall quantity or part of the high pressure air after cooling the atleast one of the high temperature sections of the gas turbine to the aircompressor.

[0180] In this aspect, the re-circulation system includes a valveopening control unit which calculates a pressure ratio of the pressurerising compressor in response to a pressure signal from each of an inletside and an outlet side of the pressure rising compressor, a rotationalspeed signal of a gas turbine shaft, a power signal of the drivenequipment, a temperature signal of the high pressure air recovered tothe air compressor, then computes the valve opening signal so that thepressure ratio becomes a specified value determined by at least one ofthe rotational speed signal of the gas turbine shaft, the power signalof the driven equipment, the temperature signal of the high pressure airrecovered to the air compressor, and supplies the operational signal tothe re-circulation valve.

[0181] In a still further aspect, there is provided a gas turbine plantcomprising:

[0182] an air compressor;

[0183] a gas turbine including at least one high temperature section;

[0184] a driven equipment, the air compressor, the gas turbine and thedriven equipment being operatively connected in series;

[0185] a gas turbine combustor arranged between the air compressor andthe gas turbine;

[0186] a fuel system for supplying a fuel to the gas turbine combustor,the fuel system being provided with a fuel valve;

[0187] a high pressure air supply system operatively connected to thehigh temperature section of the gas turbine for supplying a highpressure air from the air compressor thereto;

[0188] a heat exchange section provided for the high pressure air supplysystem for heating the fuel supplied to the gas turbine combustor fromthe fuel system;

[0189] a pressure rising compressor for rising a pressure of the highpressure air after heating the fuel and for supplying the high pressureair to at least one of the high temperature sections of the gas turbineas a cooling medium; and

[0190] at least one high pressure air recovery system provided with ahigh pressure air recovery check valve for recovering an overallquantity or part of the high pressure air after cooling the at least oneof the high temperature sections of the gas turbine to the aircompressor, the pressure rising compressor being provided with a bypasssystem including a check valve and a valve opening control unit whichcloses the fuel valve of the fuel system when an accident happens in thepressure rising compressor while opening a discharge valve provided onan inlet side of the high pressure air recovery check valve of the highpressure air recovery system.

[0191] In this aspect, the valve opening control unit serves to closethe fuel valve of the fuel system in response to the pressure signalfrom each of an inlet side and an outlet side of the pressure risingcompressor and a rotational speed signal of a pressure rising compressordriving equipment while opening a discharge valve provided on the inletside of the high pressure air recovery check valve of the high pressureair recovery system.

[0192] In a still further aspect, there is provided a gas turbine plantcomprising:

[0193] an air compressor;

[0194] a gas turbine including at least one high temperature section;

[0195] a driven equipment, the air compressor, the gas turbine and thedriven equipment being operatively connected in series;

[0196] a gas turbine combustor arranged between the air compressor andthe gas turbine;

[0197] a fuel system for supplying a fuel to the gas turbine combustor,the fuel system being provided with a fuel valve;

[0198] a high pressure air supply system operatively connected to thehigh temperature section of the gas turbine for supplying a highpressure air from the air compressor thereto;

[0199] a heat exchange section provided for the high pressure air supplysystem for heating the fuel supplied to the gas turbine combustor fromthe fuel system;

[0200] a pressure rising compressor for rising a pressure of the highpressure air after heating the fuel and for supplying the high pressureair to at least one of the high temperature sections of the gas turbineas a cooling medium;

[0201] at least one high pressure air recovery system provided with ahigh pressure air recovery check valve for recovering an overallquantity or part of the high pressure air after cooling the at least oneof the high temperature sections of the gas turbine to the aircompressor;

[0202] an accumulator which has a flow control valve on an outlet sideof the check valve on the outlet side of the pressure rising compressor;and

[0203] a valve opening control unit adapted to close the fuel valve ofthe fuel system when an accident happens in the pressure risingcompressor while opening a discharge valve provided on an inlet side ofthe high pressure air recovery check valve of the high pressure airrecovery system and adapted to open the flow control valve so that anaccumulated air from the accumulator is supplied to the at least one ofthe high temperature sections of the gas turbine.

[0204] In a still further aspect, there is provided a gas turbine plantcomprising:

[0205] an air compressor;

[0206] a gas turbine including at least one high temperature section;

[0207] a driven equipment, the air compressor, the gas turbine and thedriven equipment being operatively connected in series;

[0208] a gas turbine combustor arranged between the air compressor andthe gas turbine;

[0209] a fuel system for supplying a fuel to the gas turbine combustor;

[0210] a high pressure air supply system operatively connected to thehigh temperature section of the gas turbine for supplying a highpressure air from the air compressor thereto;

[0211] a heat exchange section provided for the high pressure air supplysystem for heating the fuel supplied to the gas turbine combustor fromthe fuel system;

[0212] a pressure rising compressor for rising a pressure of the highpressure air after heating the fuel and for supplying the high pressureair to at least one of the high temperature sections of the gas turbineas a cooling medium;

[0213] at least one high pressure air recovery system provided with ahigh pressure air recovery check valve for recovering an overallquantity or part of the high pressure air after cooling the at least oneof the high temperature sections of the gas turbine to the aircompressor; and

[0214] a valve opening control unit adapted to open a discharge valveprovided on an outlet side of the pressure rising compressor when anaccident happens in the pressure rising compressor so that a residualhigh pressure air of the air compressor conversely flows into the atleast one of the high temperature sections of the gas turbine andadapted to open the discharge valve provided on an inlet side of theheat exchange section.

[0215] According to the present invention of the various aspectsmentioned above, in the gas turbine plant according to the presentinvention, the high pressure air of the air compressor is used as aheating source for heating a fuel supplied from the fuel section to thegas turbine combustor. Further, the gas turbine plant is provided withmeans for cooling the high temperature sections of the gas turbine byreusing the high pressure air which has been used for heating the fuel.Therefore, the quantity of heat (energy) of fuel increases while theplant heat efficiency being improved, and it is possible to sufficientlydeal with the high output accompanying with the high temperature gasturbine drive gas supplied to the gas turbine.

[0216] Further, in the gas turbine plant according to the presentinvention, in the case where the high pressure air from the aircompressor is used as a heating source so as to heat the fuel, there isprovided a heat exchange section, and the heat exchange section isprovided with safety means. Therefore, the gas turbine plant can besafely operated without giving any hindrance to other components.

[0217] Further, in the gas turbine plant according to the presentinvention, in the case where the high pressure air which has been usedfor heating the fuel is reused as a cooling medium for cooling the gasturbine high temperature section, there is provided a pressure risingcompressor, and the pressure rising compressor includes means capable oftaking sufficient measures if an accident happens in the pressure risingcompressor. Therefore, it is possible to securely cool the hightemperature section of the gas turbine, and to keep the materialstrength of the high temperature section at a preferable state.

[0218] It is to be noted that the nature and further characteristicfeatures of the present invention will be made more clear from thefollowing descriptions made with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0219] In the accompanying drawings:

[0220]FIG. 1 is a system diagram schematically showing a gas turbineplant according to a first embodiment of the present invention;

[0221]FIG. 2 is a system diagram schematically showing a modifiedembodiment of the gas turbine plant according to a first embodiment ofthe present invention;

[0222]FIG. 3 is a schematically cross sectional view of a heat exchangesection cut along an arrow III-III in FIG. 2;

[0223]FIG. 4 is a system diagram schematically showing a gas turbineplant according to a second embodiment of the present invention;

[0224]FIG. 5 is a system diagram schematically showing a gas turbineplant according to a third embodiment of the present invention;

[0225]FIG. 6 is a system diagram schematically showing a gas turbineplant according to a fourth embodiment of the present invention;

[0226]FIG. 7 is a system diagram schematically showing a first modifiedembodiment of the gas turbine plant according to the fourth embodimentof the present invention;

[0227]FIG. 8 is a system diagram schematically showing a second modifiedembodiment of the gas turbine plant according to the fourth embodimentof the present invention;

[0228]FIG. 9 is a system diagram schematically showing a third modifiedembodiment of the gas turbine plant according to the fourth embodimentof the present invention;

[0229]FIG. 10 is a system diagram schematically showing a fourthmodified embodiment of the gas turbine plant according to the fourthembodiment of the present invention;

[0230]FIG. 11 is a system diagram schematically showing a fifth modifiedembodiment of the gas turbine plant according to the fourth embodimentof the present invention;

[0231]FIG. 12 is a system diagram schematically showing a sixth modifiedembodiment of the gas turbine plant according to the fourth embodimentof the present invention;

[0232]FIG. 13 is a system diagram schematically showing a seventhmodified embodiment of the gas turbine plant according to the fourthembodiment of the present invention;

[0233]FIG. 14 is a system diagram schematically showing an eighthmodified embodiment of the gas turbine plant according to the fourthembodiment of the present invention;

[0234]FIG. 15 is a system diagram schematically showing a gas turbineplant according to a fifth embodiment of the present invention;

[0235]FIG. 16 is a system diagram schematically showing a gas turbineplant according to a sixth embodiment of the present invention;

[0236]FIG. 17 is a system diagram schematically showing a gas turbineplant according to a seventh embodiment of the present invention;

[0237]FIG. 18 is a system diagram schematically showing a gas turbineplant according to an eighth embodiment of the present invention;

[0238]FIG. 19 is a system diagram schematically showing a first modifiedembodiment of the heat exchange section of the gas turbine plantaccording to the present invention;

[0239]FIG. 20 is a system diagram schematically showing a secondmodified embodiment of the heat exchange section of the gas turbineplant according to the present invention;

[0240]FIG. 21 is a system diagram schematically showing a gas turbineplant according to a ninth embodiment of the present invention;

[0241]FIG. 22 is a system diagram schematically showing a gas turbineplant according to a tenth embodiment of the present invention;

[0242]FIG. 23 is a system diagram schematically showing a modifiedembodiment of the gas turbine plant according to the tenth embodiment ofthe present invention;

[0243]FIG. 24 is a system diagram schematically showing a gas turbineplant according to an eleventh embodiment of the present invention;

[0244]FIG. 25 is a system diagram schematically showing a first modifiedembodiment of the gas turbine plant according to the eleventh embodimentof the present invention;

[0245]FIG. 26 is a system diagram schematically showing a secondmodified embodiment of the gas turbine plant according to the eleventhembodiment of the present invention;

[0246]FIG. 27 is a system diagram schematically showing a third modifiedembodiment of the gas turbine plant according to the eleventh embodimentof the present invention;

[0247]FIG. 28 is a graph showing a comparative result in a plant heatefficiency between the gas turbine plant according to each embodiment ofthe present invention and the prior art; and

[0248]FIG. 29 is a system diagram schematically showing a conventionalgas turbine plant which combines a steam turbine plant and an exhaustheat recovery boiler.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0249] Embodiments of a gas turbine plant according to the presentinvention will be described hereunder with reference to the accompanyingdrawings and reference numerals shown in these drawings.

[0250]FIG. 1 is a system diagram schematically showing a gas turbineplant according to a first embodiment of the present invention.

[0251] A gas turbine plant 7 includes an air compressor 8, a gas turbinecombustor 9, a gas turbine 10, a driven equipment 11 such as agenerator, and a fuel section 12.

[0252] In the gas turbine plant 7, an air AR sucked in the aircompressor 8 is made high in pressure, and the high pressure air (highlypressurized air) is supplied to the gas turbine combustor 9 togetherwith a fuel F from the fuel section 12. A gas turbine driving combustiongas (main flow gas) generated by the gas turbine combustor 9 is suppliedto the gas turbine 10, and then, the gas turbine combustion gas isexpanded so as to rotate and drive the driven equipment 11 with arotating torque generated in the expanding process.

[0253] On the other hand, the fuel section 12 includes a fuel tank 13, afuel pump 14, and a fuel valve 15, and in this structure, the fuelsection 12 may be called a fuel supply section or system. A heatexchange section (heat exchanger or heat exchanging unit) 16 is providedfor the air compressor 8. The fuel F from the fuel tank 13 ispressurized by the fuel pump 14, and then, a flow rate of the fuel F iscontrolled by the fuel valve 15. Thereafter, a high pressure air (highlypressurized air) of the air compressor 8 makes heat exchange in the heatexchange section 16 so as to be used as a heating source, and at thistime, the fuel F is increased in its quantity of heat (energy) and issupplied to the gas turbine combustor 9. Incidentally, a recent aircompressor has a pressure ratio of 15 or more, and a high pressure airtemperature of 400° C. or more corresponding to the pressure ratio.Therefore, the air compressor can be sufficiently used as a heatingsource with respect to a temperature for heating fuel, that is, about350° C.

[0254] As described above, in this first embodiment, when heating thefuel F, the high pressure air of the air compressor 8 is used as aheating source. Thus, the heating source can be readily obtained, and aflow rate of fuel can be relatively reduced without giving any influenceto other constituent equipments as compared with the conventional case,and therefore, a plant heat efficiency can be improved.

[0255]FIG. 2 is a diagram schematically showing a modified embodiment ofthe heat exchange section 16 according to the present invention. In thiscase, like reference numerals are used to designate the same componentsas the first embodiment or the corresponding part, and the overlappingexplanation is omitted.

[0256] The heat exchange section 16 of this embodiment is provided at acasing 17 of the air compressor 8. The heat exchange section 16 isconstructed in the following manner. More specifically, as shown in FIG.3, an outer cover 18 is formed concentrically with the casing 17 of theair compressor 8 so as to form a fuel passage 19, and one side of thefuel passage 19 is provided with a fuel inlet 22 and a fuel outlet 23.Further, the other side of the fuel passage 19 is provided with aconnecting pipe 21, and a high pressure air passing through aircompressor stationary blades 24 is used as a heating source so as toheat the fuel F passing through the fuel passage 19. Incidentally, areference numeral 20 denotes a flange, and a reference numeral 25denotes a rotary shaft (rotor).

[0257] In this embodiment, even though the heat exchange section 16 isprovided on the casing 17 of the air compressor 8, the temperature ofhigh pressure air is high as described above, so that the fuel F can besufficiently and preferably heated.

[0258]FIG. 4 is a system diagram schematically showing a gas turbineplant according to a second embodiment of the present invention.Incidentally, like reference numerals are used to designate the samecomponents as the first embodiment or the corresponding parts.

[0259] In this embodiment, an air extraction closed (circuit) system 26is provided at an outlet or a high pressure stage of the air compressor.The air extraction closed system 26 includes the heat exchanger section16, and a high pressure air which has been used for heating the fuel Fis recovered to an inlet or a low pressure stage of the air compressor8.

[0260] As described above, in this embodiment, the fuel F is heated withthe utilization of the air extraction of the air compressor 8, and theextracted air is recovered to the air compressor 8. Therefore, a heatingsource is effectively used, so that a plant heat (thermal) efficiencycan be improved.

[0261]FIG. 5 is a diagram schematically showing a gas turbine plantaccording to a third embodiment of the present invention. Incidentally,like reference numerals are used to designate the same components as thefirst embodiment or the corresponding parts.

[0262] In this embodiment, the heat exchange section 16 is provided atan exhaust gas system 27 on an outlet side of the gas turbine 10.

[0263] In general, in an open cycle gas turbine, a gas turbine drivinggas (main flow gas) expanded in the gas turbine 10 is discharged intoatmosphere. The temperature of the exhaust gas (exhaust heat) is about600° C. and is extremely high.

[0264] In this embodiment, the high temperature exhaust gas has beentaken into consideration. The exhaust gas from the gas turbine 10 isused as a heating source, and then, the fuel F from the fuel section 12is heated in the heat exchange section 16.

[0265] As described above, in this embodiment, a heat of the exhaust gasfrom the gas turbine 10 is effectively used, and a quantity of heat ofthe fuel F is made high, and thus, the fuel flow rate is relativelyreduced as compared with the conventional case. Therefore, a plant heatefficiency can be greatly improved as compared with the conventionalcase.

[0266]FIG. 6 is a system diagram schematically showing a gas turbineplant according to a fourth embodiment of the present invention.Incidentally, like reference numerals are used to designate the samecomponents as the first embodiment or the corresponding parts.

[0267] In this embodiment, the following matter has been taken intoconsideration. More specifically, when reusing a high pressure air whichhas been used for heating the fuel F for cooling high temperaturesections 31 a and 31 b of the gas turbine 10, the high pressure airpreferably flows depending upon magnitudes of presser losses in thesehigh temperature sections 31 a and 31 b. There is provided a highpressure air supply system 29 which is bypassed to a air feed system 28for supplying a high pressure air from the outlet side of the aircompressor 8 to the gas turbine combustor 9. The high pressure airsupply system 29 is provided at its intermediate portions with the heatexchange section 16 of the fuel section 12 and flow distributing devices30 a and 30 b, and the high pressure air supply system 29 is dividedinto a first high pressure air supply system 29 a and a second highpressure air supply system 29 b. Each of the first and second supplysystems 29 a and 29 b are connected to the high temperature sections 31a and 31 b of the gas turbine 10, for example, to gas turbine stationaryblades and gas turbine rotating blades, etc. Further, there is provideda high pressure air recovery system 32 which recovers the overallquantity or a part of the high pressure air which has been used forcooling the high temperature sections 31 a and 31 b of the gas turbineto the air compressor 8. In this case, although the high pressure airsupply system 29 is bypassed from the air feed system 26, it may beprovided at an intermediate stage of the air compressor 8. Moreover, twohigh temperature section 31 a and 31 b of the gas turbine 10 are shownas an example. Two or more high temperature sections may be provided.The flow distributing devices 30 a and 30 b are constituted specificallyas flow control valves or orifices. In the case of using the orifices, ahole diameters of the orifices are set so as to meet with flow ratesrequired for the high temperature sections 31 a and 31 b.

[0268] In this embodiment, the fuel F from the fuel section 12 is heatedby the high pressure air from the air compressor 8, and after the fuel Fis heated, the high temperature sections 31 a and 31 b of the gasturbine 10 are cooled by the high pressure air whose temperature becomeslow. Further, the overall quantity or part of the high pressure airwhich has been used for cooling is recovered to the air compressor 8, sothat heat can be effectively used. Therefore, a plant heat efficiency isimproved, and it is possible to maintain a material strength of the hightemperature sections 31 a and 31 b of the gas turbine 10 while the gasturbine plant 7 being made high temperature.

[0269]FIG. 7 is a system diagram schematically showing a first modifiedembodiment of the gas turbine plant according to the fourth embodimentof the present invention. In this case, like reference numerals are usedto designate the same components as the fourth embodiment or thecorresponding part.

[0270] In this embodiment, the high pressure air which has been used forcooling the high temperature sections 31 a and 31 b of the gas turbine10 is joined together with a gas turbine driving gas G (main flow gas).

[0271] In this embodiment, the high pressure air which has been used forcooling the high temperature sections 31 a and 31 b of the gas turbine10 is joined together with a gas turbine driving gas G so as to increasethe driving gas G. Thus, there is an expansion work of the gas turbine10 is increased, being advantageous.

[0272]FIG. 8 is a system diagram schematically showing a second modifiedembodiment of the gas turbine plant according to the fourth embodimentof the present invention. In this case, like reference numerals are usedto designate the same components as the fourth embodiment or thecorresponding part.

[0273] In this embodiment, there is provided the high pressure airrecovery system 32 for recovering the high pressure air which has beenused for cooling the high temperature sections 31 a and 31 b of the gasturbine 10 from the first high pressure air supply system 29 a and thesecond high pressure air supply system 29 b to the air compressor 8. Thehigh pressure air recovery system 32 is divided into a first highpressure air recovery system 32 a and a second high pressure airrecovery system 32 b. The first high pressure air recovery system 32 aand the second high pressure air recovery system 32 b are connected to arelatively high pressure stage of the air compressor 8 and to arelatively low pressure stage of the air compressor 8, respectively.

[0274] As described above, in this embodiment, when recovering theoverall quantity or part of the high pressure air which has been usedfor cooling the high temperature sections 31 a and 31 b of the gasturbine 10 to the air compressor 8 via each of the recovery systems 32 aand 32 b, the high pressure air is recovered so as to meet with apressure level of a driving air of the air compressor 8. Thus, even if apressure difference differs between the high temperature sections 31 aand 31 b of the gas turbine 10, the high pressure air of a properquantity can be allowed to flow.

[0275]FIG. 9 is a system diagram schematically showing a third modifiedembodiment of the gas turbine plant according to the fourth embodimentof the present invention. In this case, like reference numerals are usedto designate the same components as the fourth embodiment or thecorresponding part.

[0276] In this embodiment, a pressure rising compressor 33 is providedin the high pressure air supply system 29 which is divided into thefirst high pressure air supply system 29 a and the second high pressureair supply system 29 b. In the heat exchange section 16 of the fuelsection 12, the high pressure air from the air compressor 8 is used as aheating source to heat the fuel F, and then, the high pressure air whosetemperature becomes low is made high in pressure and is supplied as acooling medium for cooling the high temperature sections 31 a and 31 bof the gas turbine 10.

[0277] As described above, in this embodiment, the high pressure airwhose temperature and pressure become low, which has been used forcooling the fuel F is elevated in its pressure by the pressure risingcompressor 33, so that the high pressure air can be securely supplied tothe high temperature sections 31 a and 31 b of the gas turbine 10.Therefore, the high temperature sections 31 a and 31 b of the gasturbine 10 can be securely cooled.

[0278]FIG. 10 is a system diagram schematically showing a fourthmodified embodiment of the gas turbine plant according to the fourthembodiment of the present invention. In this case, like referencenumerals are used to designate the same components as the fourthembodiment or the corresponding part.

[0279] In this embodiment, the pressure rising compressor 33 is providedin the high pressure air supply system 29 which is divided into thefirst high pressure air supply system 29 a and the second high pressureair supply system 29 b, and further, there is provided the high pressureair recovery system 32 for recovering the overall quantity or part ofhigh pressure air which has been used for cooling the high temperaturesections 31 a and 31 b of the gas turbine 10 to the air compressor 8.The high pressure air recovery system 32 is divided into a first highpressure air recovery system 32 a and a second high pressure airrecovery system 32 b.

[0280] As described above, in this embodiment, the high pressure airsupply system 29 is provided with the pressure rising compressor 33, andthe fuel F is heated by the heat exchange section 16 of the fuel section12, and further, the high pressure air whose temperature becomes low isheightened in its pressure, and thus, is supplied to the hightemperature sections 31 a and 31 b of the gas turbine 10 as a coolingmedium for cooling them. Then, the overall quantity or part of the highpressure air whose pressure becomes low which has been used for coolingthe high temperature sections 31 a and 31 b of the gas turbine 10, isrecovered to the air compressor 8 via the high pressure air recoverysystem 32 divided into the first high pressure air recovery system 32 aand the second high pressure air recovery system 32 b. Therefore, a heatof the high pressure air of the air compressor 8 is effectively used, sothat a plant heat efficiency can be improved as compared with theconventional case.

[0281]FIG. 11 is a system diagram schematically showing a fifth modifiedembodiment of the gas turbine plant according to the fourth embodimentof the present invention. In this case, like reference numerals are usedto designate the same components as the fourth embodiment or thecorresponding part.

[0282] In this embodiment, the high pressure air supply system 29 isdivided into the first high pressure air supply system 29 a and thesecond high pressure air supply system 29 b, and these supply systems 29a and 29 b are individually provided with a first pressure risingcompressor 33 a and a second pressure rising compressor 33 b. Further,the second high pressure air supply system 29 b is bypassed from anoutlet side of the first pressure rising compressor 33 a.

[0283] As described above, in this embodiment, these supply systems 29 aand 29 b are individually provided with the first pressure risingcompressor 33 a and the second pressure rising compressor 33 b, andfurther, the second high pressure air supply system 29 b is bypassedfrom the outlet side of the first pressure rising compressor 33 a. Thus,the fuel F is heated by the heat exchange section 16 of the fuel section12, and it is possible to securely supply the high pressure air whosetemperature becomes low to the high temperature sections 31 a and 31 b.Therefore, each of the high temperature sections 31 a and 31 b can besecurely cooled.

[0284]FIG. 12 is a system diagram schematically showing a sixth modifiedembodiment of the gas turbine plant according to the fourth embodimentof the present invention. In this case, like reference numerals are usedto designate the same components as the fourth embodiment or thecorresponding part.

[0285] In this embodiment, the high pressure air supply system 29 isdivided into the first high pressure air supply system 29 a and thesecond high pressure air supply system 29 b which are arranged inparallel. In these supply systems 29 a and 29 b, the first high pressureair supply system 29 a is provided with the first pressure risingcompressor 33 a, and the second high pressure air supply system 29 b isprovided with the second pressure rising compressor 33 b.

[0286] In this embodiment, these supply systems 29 a and 29 b areprovided with the pressure rising compressors 33 a and 33 b,respectively. Thus, like the fifth modified embodiment of the fourthembodiment, the fuel F is heated by the heat exchange section 16 of thefuel section 12, and it is possible to securely supply the high pressureair whose temperature becomes low to the high temperature sections 31 aand 31 b. Therefore, it is possible to sufficiently meet with the gasturbine 10 of the gas turbine plant 7 heated to a high temperature.

[0287]FIG. 13 is a system diagram schematically showing a seventhmodified embodiment of the gas turbine plant according to the fourthembodiment of the present invention. In this case, like referencenumerals are used to designate the same components as the fourthembodiment or the corresponding part.

[0288] In this embodiment, the following matter is taken intoconsideration. Specifically, a pressure loss in the high pressure airpassing through the high temperature section 31 b situated on a lowpressure stage of the gas turbine 10, is relatively small. The highpressure air supply system 29 is divided into the first high pressureair supply system 29 a and the second high pressure air supply system 29b which are arranged in parallel, and only the first high pressure airsupply system 29 a is provided with the pressure rising compressor 33.Further, there is provided the high pressure air recovery system 32 forrecovering the overall quantity or part of the high pressure air whichhas been used for cooling the high temperature sections 31 a and 31 b ofthe gas turbine 10 to the air compressor 8. Then, the high pressure airrecovery system 32 is divided into the first high pressure air recoverysystem 32 a and the second high pressure air recovery system 32 b. Thefirst high pressure air recovery system 32 a and the second highpressure air recovery system 32 b are connected to a high pressure stageside of the air compressor 8 and to a low pressure stage side of the aircompressor 8, respectively.

[0289] Therefore, in this embodiment, the fuel F is heated by the heatexchange section 16 of the fuel section, and the high pressure air whosetemperature becomes low can be securely supplied to the high temperaturesections 31 a and 31 b of the gas turbine 10. Further, when recoveringthe overall quantity or part of the high pressure air which has beenused for cooling the high temperature sections 31 a and 31 b of the gasturbine 10, the high pressure air can be preferably recovered withoutgiving a fluctuation to a driving air of the air compressor 8.

[0290]FIG. 14 is a system diagram schematically showing an eighthmodified embodiment of the gas turbine plant according to the fourthembodiment of the present invention. In this case, like referencenumerals are used to designate the same components as the fourthembodiment or the corresponding part.

[0291] In this embodiment, the high pressure air supply system 29 isdivided into the first high pressure air supply system 29 a and thesecond high pressure air supply system 29 b, and the pressure risingcompressor 33 is provided so as to correspond to the inlets of thedivided first high pressure air supply system 29 a and second highpressure air supply system 29 b. There are further provided the highpressure air recovery system 32 for recovering the overall quantity orpart of the high pressure air from the first high pressure air supplysystem 29 a which has been used for cooling the high temperature section31 a on a relatively high pressure stage side of the gas turbine 10 tothe outlet side of the air compressor 8, and a cooling recovery system24 for recovering the overall quantity or part of the high pressure airfrom the second high pressure air supply system 29 b which has been usedfor cooling the high temperature section 31 b on a relatively lowpressure stage side of the gas turbine 10, to the inlet side of the heatexchange section 16 of the fuel section 12.

[0292] As described above, in this embodiment, the high pressure airsupply system 29 is provided with the pressure rising compressor 33, andthe outlet side of the pressure rising compressor 33 is divided into thefirst high pressure air supply system 29 a and the second high pressureair supply system 29 b. Further, the fuel F is heated by the heatexchange section 16 of the fuel section 12, and then, the high pressureair whose temperature becomes low is elevated in its pressure by thepressure rising compressor 33, and thus, is supplied to the hightemperature sections 31 a and 31 b of the gas turbine 10 via therespective high pressure air supply systems 29 a and 29 b. Furthermore,the overall quantity or part of the high pressure air which has beenused for cooling the high temperature sections 31 a and 31 b of the gasturbine 10 is recovered to the air compressor 8 via the high pressureair recovery system 32, and then, the overall quantity or part of thehigh pressure air after cooling them is recovered to the inlet side ofthe heat exchange section 16 via the cooling recovery system 34.Therefore, a heat is effectively used, so that a plant heat efficiencycan be greatly improved more than conventional case.

[0293]FIG. 15 is a system diagram schematically showing a gas turbineplant according to a fifth embodiment of the present invention. In thiscase, like reference numerals are used to designate the same componentsas the first embodiment or the corresponding part.

[0294] In this embodiment, there is provided the high pressure airsupply system 29 which is constructed in such a manner that an airsupply system 28 for supplying the high pressure air from the aircompressor 8 to the gas turbine combustor 9, is bypassed thereto. Thehigh pressure air supply system 29 is provided with the heat exchangesection 16 of the fuel section 12, and a heat utilizing device 36, forexample, a heat exchange section 37 for co-generation heat recoverydevice. The high pressure air supply system 29 is further provided withflow distributing devices 30 a and 30 b so as to be divided into thefirst high pressure air supply system 29 a and the second high pressureair supply system 29 b. The divided first and second high pressure airsupply systems 29 a and 29 b are connected to the high temperaturesections 31 a and 31 b of the gas turbine 10, respectively.

[0295] According to the construction of this embodiment mentioned above,a part of the high pressure air supplied from the air supply system 28of the air compressor 8 to the gas turbine combustor 9 is distributed tothe high pressure air supply system 29, and then, the fuel F suppliedfrom the fuel section 12 to the gas turbine combustor 9 is heated by theheat exchange section 16. Next, a medium to be heated from the heatutilizing device 36, for example, a cooling water, is heated by the heatexchange section 37 for heat utilizing device, and further, cools thehigh temperature sections 31 a and 31 b of the gas turbine 10 via theflow distributing devices 30 a and 30 b of the first and second highpressure air supply systems 29 a and 29 b, and thereafter, is recoveredfrom the high temperature sections 31 a and 31 b to the air compressor 8via the high pressure air recovery system 32.

[0296] As described above, in this embodiment, a part of the highpressure air supplied from the air supply system 28 of the aircompressor 8 to the gas turbine combustor 9 is bypassed, and then, thebypassed high pressure air is used as a heating source so that the fuelF from the fuel section 12 is heated in the heat exchange section 16.Next, the medium to be heated from the heat utilizing device 36 isheated in the heat exchange section 37, and finally, the high pressureair whose temperature becomes low is used as a cooling source so thatthe high temperature sections 31 a and 31 b of the gas turbine 10 can becooled. Therefore, the heat of the high pressure air can be effectivelyused for multi-purpose.

[0297]FIG. 16 is a system diagram schematically showing a gas turbineplant according to a sixth embodiment of the present invention. In thiscase, like reference numerals are used to designate the same componentsas the first embodiment or the corresponding part.

[0298] In this embodiment, an air extraction closed system 35 isprovided on a high pressure stage side of the air compressor 8. The airextraction closed system 35 is provided with the heat exchange section16 of the fuel section 12, and the heat utilizing device 36, forexample, the heat exchange section 37 for co-generation heat utilizingdevice. Then, the high pressure air from the air compressor 8 is used asa heating source so that the fuel F from the fuel section is heated inthe heat exchange section 16. Further, a medium to be heated from theheat utilizing device 36, for example, a cooling water CW, is heated inthe heat exchange section 37 for the heat utilizing device, and then,the high pressure air is recovered to the air compressor 8.

[0299] As described above, in this embodiment, the air compressor 8 isprovided with the air extraction closed system 35, and the airextraction closed system 35 is provided with the heat exchange section16 of the fuel section 12, the heat utilizing device 36 and the heatexchange section 37 for the heat utilizing device. Further, the highpressure air extracted from the air compressor 8 is used as a heatingsource so that the fuel F from the fuel section 12 is heated in the heatexchange section 16, and then, a medium to be heated from the heatutilizing device 36 is heated in the heat exchange section 37 for heatutilizing device. Therefore, the heat of high pressure air can beeffectively used for multi-purpose.

[0300]FIG. 17 is a system diagram schematically showing a gas turbineplant according to a seventh embodiment of the present invention. Inthis case, like reference numerals are used to designate the samecomponents as the first embodiment or the corresponding part.

[0301] In this embodiment, the gas turbine plant 0.7 is combined with asteam turbine plant 38, and an exhaust gas system 39 of the gas turbine10 is provided with a first exhaust heat recovery heat exchanger 44 anda second exhaust heat recovery heat exchanger 43 of the steam turbineplant 38, and the heat exchange section 16 of the fuel section 12.

[0302] The steam turbine plant 38 is a so-called single-shaft type whichis constructed in such a manner that the gas turbine 10 is connected inshaft directly to a steam turbine 40 via a driven equipment 11, forexample, a generator. Further, the steam turbine plant 38 is formed as aclosed circuit system including a condenser 41, a pump 42, the secondexhaust heat recovery heat exchanger 43 and the first exhaust heatrecovery heat exchanger 44. A feed water supplied from the pump 42 isheated (preheated) by the second exhaust heat recovery heat exchanger 43with the use of an exhaust gas (exhaust heat) discharged from theexhaust gas system 39 of the gas turbine 10 to atmospheric air as aheating source. Further, the heated water is heated by the first exhaustheat recovery heat exchanger 44 using the exhaust gas of the heatexchanger 43 as a heating source, and thereby, the heated water is madeinto a steam, and the steam is supplied to the steam turbine 40, andthus, a power is generated. In this embodiment, the heat exchangersection 16 has been disposed between the first exhaust heat recoveryheat exchanger 44 and the second exhaust heat recovery heat exchanger43, as an example. The heat exchanger section 16 may be disposed on anupstream side of the first exhaust heat recovery heat exchanger 44 ormay be disposed on a downstream side of the second exhaust heat recoveryheat exchanger 43.

[0303] As described above, in this embodiment, the exhaust gas system 39of the gas turbine 10 is provided with the first exhaust heat recoveryheat exchanger 44 and the second exhaust heat recovery heat exchanger 43of the steam turbine plant 38 and the heat exchange section 16 of thefuel section 12 so as to generate a steam and heat the fuel F, and theheat of exhaust gas is sufficiently used. Therefore, a plant heatefficiency can be greatly improved by a small quantity of fuel ascompared with the conventional case.

[0304]FIG. 18 is a system diagram schematically showing a gas turbineplant according to an eighth embodiment of the present invention. Inthis case, like reference numerals are used to designate the samecomponents as the first embodiment or the corresponding part.

[0305] In this eighth embodiment, the following matter is taken intoconsideration. More specifically, when the high pressure air extractedfrom the air compressor 8 is used as a heating source and the fuel F isheated in the heat exchange section 16 of the fuel section 12, in thecase where the fuel F leaks into the high pressure air, this is a factorof causing an accident. For this reason, the heat exchange section 16 isprovided with a fuel leak detector 45, a valve opening control section46, an alarm device 47 and a fuel leak display device (indicator) 48.

[0306] The valve opening control section 46 is constructed so as toclose a fuel valve 15 if a fuel leak signal detected by the fuel leakdetector 45 exceeds a predetermined value. The alarm device 47 alsogives the alarm if a fuel leak signal detected by the fuel leak detector45 exceeds a predetermined value. The fuel leak display 48 displays aleaked fuel concentration detected by the fuel leak detector 45 so thata worker can visibly confirm the fuel leakage.

[0307] As described above, in this embodiment, if the leakage of fuel Fexceeds a predetermined value, the alarm is given, and further, the fuelvalve 15 is automatically closed. Therefore, the gas turbine combustor 9can be safely operated without operating the gas turbine combustor 9 ina state that the fuel leaks.

[0308]FIG. 19 is a view schematically showing a first modifiedembodiment of the heat exchange section 16 in the gas turbine plantaccording to the present invention.

[0309] In general, in the heat exchange section 16, a fuel flows througha heat-transfer pipe, and a heating medium flows outside theheat-transfer pipe. In the heat exchange section 16 of this embodiment,a fuel leakage from the heat-transfer pipe is taken into consideration.More specifically, the heat exchange section 16 is divided into a firstheat exchange section 49 and a second heat exchange section 50. Further,a high temperature heating medium HG flows through the first heatexchange section 49 while an intermediate heating medium IG, forexample, an inert gas such as nitrogen gas or the like being supplied tothe second heat exchange section 50 so that the fuel F is heated. Then,the intermediate heating medium IG heated the fuel F is circulated intothe first heat exchange section 49 via a pump 51.

[0310] As described above, the heat exchange section 16 of thisembodiment is divided into the first heat exchange section 49 and thesecond heat exchange section 50, and the fuel F is heated by theintermediate heating medium IG. Thus, even in the event that a fuelleakage occurs in the second heat exchange section 50, it is possible toprevent an accident such as explosion or the like, and there is nodanger as compared with the conventional indirect heat exchanger, thusbeing advantageous.

[0311]FIG. 20 is a view schematically showing a second modifiedembodiment of the heat exchange section 16 in the gas turbine plantaccording to the present invention. The heat exchange section 16 of thisembodiment is divided into a high temperature chamber 52 and a lowtemperature chamber 53 and is attached with a heat pipe 54 in a mannerof crossing these chambers 52 and 53. The high temperature heatingmedium HG supplied to the high temperature chamber 52 heats the heatpipe 54, and then, the heat is transferred to the fuel F of the lowtemperature chamber 53 so as to heat the fuel F. Thus, even in the eventthat a fuel leakage occurs, there is no possibility of explosion, sothat a safe operation of the heat exchange section 16 can be securelyperformed.

[0312]FIG. 21 is a system diagram schematically showing a gas turbineplant according to a ninth embodiment of the present invention. In thiscase, like reference numerals are used to designate the same componentsas the first embodiment or the corresponding part.

[0313] In this ninth embodiment, the high pressure air discharged fromthe air compressor 8 via a discharged air system is used as a heatingsource for heating the fuel F of the fuel section 12. A check valve 56and the heat exchange section 16 of the fuel section 12 are bypassedfrom the midway of the discharged air system 55, and thus, there isprovided a discharged air recovery system 57 connected to a low pressurestate of the air compressor 8 or to an outlet thereof.

[0314] The discharged air system 55 includes a discharged air valve 58.The discharged air valve 58 includes a valve opening control section 59.The valve opening is computed (operated) by the valve opening controlsection 59 on the basis of at least one or more signals of a rotationalspeed signal from a rotational speed detector 61 which detects arotational speed of a gas turbine shaft 60 and an operating signal froma power detector 62 which detects a power of the driven equipment 11. Inthis manner, a control for opening and closing the valve is made on thebasis of the operational signal.

[0315] As described above, in this embodiment, a flow rate of the highpressure air discharged from the air compressor 8 to the atmospheric airvia the discharged air system 55 is controlled by the discharged airvalve 58, and then, the high pressure air thus controlled in the flowrate is used as a heating source so that the fuel F of the fuel section12 is heated in the heat exchange section 16 provided in the dischargeair recovery system 57, and thus, is recovered to the air compressor 8.Therefore, the heat is effectively used, so that a plant heat efficiencycan be improved as compared with the conventional case.

[0316]FIG. 22 is a system diagram schematically showing a gas turbineplant according to a tenth embodiment of the present invention. In thiscase, like reference numerals are used to designate the same componentsas the first embodiment or the corresponding part.

[0317] In this tenth embodiment, the following matter is taken intoconsideration. More specifically, in the case where an accident happensin a driving source of the pressure rising compressor 33 provided in thehigh pressure air supply system 29 divided into the first high pressureair supply system 29 a and the second high pressure air supply system 29b, and then, the pressure rising compressor 33 is not operated, the highpressure air from the air compressor 8 is not supplied to the hightemperature sections 31 a and 31 b of the gas turbine 10 in order tocool these high temperature sections. Thus, the pressure risingcompressor 33 is connected directly to the gas turbine shaft 60.

[0318] As described above, in this embodiment, the pressure risingcompressor 33 is connected directly to the gas turbine shaft 60. Thus,the fuel F from the fuel section 12 is heated in the heat exchangesection 16 using the high pressure air from the air compressor 8, andthe high pressure air whose temperature becomes low is securely suppliedto the high temperature sections 31 a and 31 b of the gas turbine 10 viathe flow distributing devices 30 a and 30 b as a cooling medium forcooling these high temperature sections. Therefore, the gas turbine 10can be safely operated.

[0319]FIG. 23 is a system diagram schematically showing a modifiedembodiment of the gas turbine plant according to the tenth embodiment ofthe present invention. In this case, like reference numerals are used todesignate the same components as the tenth embodiment or thecorresponding part.

[0320] In this embodiment, the pressure rising compressor 33 is providedin the high pressure air supply system 29 divided into the first highpressure air supply system 29 a and the second high pressure air supplysystem 29 b, and the pressure rising compressor 33 is connected to thegas turbine shaft 60 via a power transmission mechanism section 63.Either one of gear or torque converter is selected as the powertransmission mechanism section 63.

[0321] In this embodiment, the pressure rising compressor 33 suppliesthe high temperature air from the air compressor 8 heating the fuel F inthe heat exchange section 16 of the fuel section 12 to the hightemperature sections 31 a and 31 b of the gas turbine as a coolingmedium for cooling these high temperature sections. The pressure risingcompressor 33 is connected to the gas turbine shaft 60 via the powertransmission mechanism section 63 so as to be driven by a rotatingtorque of the gas turbine shaft 60. Therefore, the pressure risingcompressor 33 can be securely driven.

[0322]FIG. 24 is a system diagram schematically showing a gas turbineplant according to an eleventh embodiment of the present invention. Inthis case, like reference numerals are used to designate the samecomponents as the first and fourth embodiments or the correspondingpart.

[0323] In this eleventh embodiment, the following matter is taken intoconsideration. More specifically, the high pressure air extracted fromthe intermediate stage of the air compressor 8 is supplied to the heatexchange section 16 of the fuel section 12 via the high pressure airsupply system 29 so as to heat the fuel F, and then, the high pressureair whose temperature becomes low is supplied to the high temperaturesections 31 a and 31 b of the gas turbine 10 as a cooling medium forcooling these high temperature sections via the pressure risingcompressor 33, the check valve 64, the flow distributing devices 30 aand 30 b. In such a case, if the high pressure air of a proper quantityis not supplied to the high temperature sections 31 a and 31 b of thegas turbine 10 in accordance with various operating conditions, thesehigh temperature sections 31 a and 31 b are burnt. Further, if thepressure ratio of the pressure rising compressor 33 is not kept at aproper value, surging is caused, and for this reason, the pressurerising compressor 33 becomes a danger state. Thus, in order to avoid theabove disadvantage, a re-circulation system 65 is provided between theoutlet side of the pressure rising compressor 33 and the inlet side ofthe check valve 64 so that a part of the high pressure air can becirculated.

[0324] In the re-circulation system 65, a bypass is made between theoutlet side of the pressure rising compressor 33 and the inlet side ofthe check valve 64, and there is provided a re-circulation valve 66 sothat the re-circulation system 65 is connected to the inlet side of theheat exchange section 16.

[0325] The re-circulation valve 66 includes a valve opening controlsection 67. The valve opening control section 67 calculates a pressureratio of the pressure rising compressor 33 in response to a pressuresignal from pressure instruments 68 a and 68 b provided on each of inletand outlet sides of the pressure rising compressor 33, a temperaturesignal from a thermometer 69 provided on the high pressure air recoverysystem 32, a rotational speed signal from the rotational speed detector61 provided on the gas turbine shaft 60, and a power signal from thepower detector 62 provided on the driven equipment 11. Further, thevalve opening control section 67 computes the valve opening signal sothat the pressure ratio becomes a specified value determined by at leastone of the rotational speed of the gas turbine shaft 60, the powersignal of the driven equipment 11, and a high pressure air signal of thehigh pressure air recovery system 32, and then, supplies the operationalsignal to the re-circulation valve 66, and thus, performs a control foropening and closing the re-circulation valve.

[0326] As described above, according to this embodiment, in thetransient state such as the rise-up of the rotational speed and therise-up of load, a part of the high pressure air of the high pressureair supply system 29 is circulated via the re-circulation system 65, andthus, the pressure ratio of the pressure rising compressor 33 is kept ata proper value, so that the high temperature sections 31 a and 31 b ofthe gas turbine 10 can be securely cooled.

[0327]FIG. 25 is a system diagram schematically showing a first modifiedembodiment of the gas turbine plant according to the eleventh embodimentof the present invention. In this case, like reference numerals are usedto designate the same components as the eleventh embodiment or thecorresponding part.

[0328] In this embodiment, the following matter is taken intoconsideration. More specifically, the high pressure air extracted fromthe intermediate stage of the air compressor 8 is supplied to the heatexchange section 16 of the fuel section 12 via the high pressure airsupply system 29 so as to heat the fuel F, and then, the high pressureair whose temperature becomes low is supplied to the high temperaturesections 31 a and 31 b of the gas turbine 10 as a cooling medium forcooling these high temperature sections via the pressure risingcompressor 33, and the flow distributing devices 30 a and 30 b. In sucha case, the pressure rising compressor 33 or a drive equipment 70 forpressure rising compressor is not operated due to any reasons. In orderto avoid such disadvantage, the pressure rising compressor 33 isprovided with a pressure rising compressor bypass system 72 including acheck valve 71, and a discharge valve 73 is provided on an inlet side ofa high pressure air recovery check valve 71 a of the high pressure airrecovery system 32. In this manner, the high temperature sections 31 aand 31 b of the gas turbine 10 are continuously cooled by a residualhigh pressure air of the air compressor 8 until the gas turbine plant 7is stopped.

[0329] If an accident happens in the pressure rising compressor 33 orthe drive equipment 70 for the pressure rising compressor and theoperation becomes impossible, the valve opening control section 67computes a valve opening signal on the basis of the pressure signal fromthe pressure instruments 68 a and 68 b and the rotational speed signalfrom a pressure rising compressor rotational speed (frequency) detector74, and then, transmits the operational signal to the discharge valve 73and the fuel valve 15 of the fuel section 12 so that the discharge valve73 is opened while the fuel valve 15 being closed. When the dischargevalve 73 is opened, the air compressor 8 supplies the residual highpressure air to the high temperature sections 31 a and 31 b of the gasturbine 10 via the high pressure air supply system 29, the check valve71 and the pressure rising compressor bypass system 72 so as to coolthese high temperature sections 31 a and 31 b. Thereafter, the residualhigh pressure air is discharged from the discharge valve 73 to theatmospheric air via the high pressure air recovery system 32. In thiscase, when the discharge valve 73 is fully opened, the pressure of thehigh pressure air passing through the high temperature sections 31 a and31 b of the gas turbine 10 lowers. However, the high pressure airrecovery check valve 71 a is provided on the downstream side of thedischarge valve 73, and therefore, the residual high pressure air fromthe air compressor 8 does not conversely flow into the discharge valve73.

[0330] As described above, in this embodiment, until an accident happensin the pressure rising compressor 33 or in the pressure risingcompressor drive equipment 70 and the gas turbine plant 7 is stopped,the high pressure air remaining in the air compressor 8 is supplied tothe high temperature sections 31 a and 31 b of the gas turbine 0.10 viathe high pressure sir supply system 29, the check valve 71 and thepressure rising compressor bypass system 72 so that these hightemperature sections 31 a and 31 b are continuously cooled. Thus, it ispossible to keep a material strength of these high temperature sections31 a and 31 b of the gas turbine 10 at a preferable state, so that thelifetime of the material can be made long.

[0331]FIG. 26 is a system diagram schematically showing a secondmodified embodiment of the gas turbine plant according to the eleventhembodiment of the present invention. In this case, like referencenumerals are used to designate the same components as the eleventhembodiment or the corresponding part.

[0332] In this embodiment, the following matter is taken intoconsideration. More specifically, the high pressure air extracted fromthe intermediate stage of the air compressor 8 is supplied to the heatexchange section 16 of the fuel section 12 via the high pressure airsupply system 29 so as to heat the fuel F, and then, the high pressureair whose temperature becomes low is supplied to the high temperaturesections 31 a and 31 b of the gas turbine 10 as a cooling medium forcooling these high temperature sections via the pressure risingcompressor 33, the check valve 64 and the flow distributing devices 30 aand 30 b. In such a case, the pressure rising compressor 33 or the driveequipment 70 for pressure rising compressor is not operated due to anyreasons. In order to avoid such disadvantage, a flow control valve 75and an accumulator 76 are provided on the outlet side of the check valve64. The high temperature sections 31 a and 31 b of the gas turbine 10are continuously cooled by an accumulated (stored) air of theaccumulator 76 until the gas turbine plant 7 is stopped.

[0333] If an accident happens in the pressure rising compressor 33 orthe drive equipment 70 for pressure rising compressor, and the operationis impossible, the valve opening control section 67 computes a valveopening signal on the basis of the pressure signal from the pressureinstruments 68 a and 68 b and the rotational speed signal from apressure rising compressor rotational speed detector 74, and then,transmits the operational signal to the discharge valve 73 provided onthe inlet side of the high pressure air recovery check valve 71 a of thehigh pressure air recovery system 32, the fuel valve 15 of the fuelsection 12 and the flow control valve 75 so that the fuel valve 15 isclosed while the discharge valve 73 and the flow control valve 75 beingopened.

[0334] As described above, in this embodiment, until an accident happensin the pressure rising compressor 33 or in the pressure risingcompressor drive equipment 70 and the gas turbine plant 7 is stopped,the accumulated air of the accumulator 76 is supplied to the hightemperature sections 31 a and 31 b of the gas turbine 10 as a back-up.Thus, it becomes possible to keep the material strength for a long termwithout giving a damage to the material of these high temperaturesections 31 a and 31 b.

[0335]FIG. 27 is a system diagram schematically showing a third modifiedembodiment of the gas turbine plant according to the eleventh embodimentof the present invention. In this case, like reference numerals are usedto designate the same components as the eleventh embodiment or thecorresponding part.

[0336] In this embodiment, like the first and second modified embodimentin the eleventh embodiment, the accident is taken into consideration.More specifically, discharge valves 77 a and 77 b are provided on thehigh pressure air supply system 29 on the inlet side of the heatexchange section 16 and the high pressure air supply system 29 on theoutlet side of the pressure rising compressor 33, respectively. If anaccident happens in the pressure rising compressor 33 or the driveequipment 70 for pressure rising compressor, according to theoperational signal from the valve opening control section 67, the fuelvalve 15 of the fuel section 12 is closed while the discharge valves 77a and 77 b being opened, and then, the high pressure air of the highpressure air supply system 29 is discharged to the atmospheric air viathese discharge valves 77 a and 77 b. Further, the high pressure airremaining in the air compressor 8 conversely flows into the hightemperature sections 31 a and 31 b of the gas turbine 10 via the highpressure air recovery system 32 so that the high temperature sections 31a and 31 b of the gas turbine 10 are cooled, and thereafter, isdischarged to the atmospheric air via the discharge valve 77 b.

[0337] As described above, in this embodiment, in the case where anaccident happens in the pressure rising compressor 33 or in the pressurerising compressor drive equipment 70, the discharge valves 77 a and 77 bare opened so that the high pressure air of the high pressure air supplysystem is discharged to the atmospheric air, and during this discharge,the high pressure air remaining in the air compressor 8 conversely flowsinto the high temperature sections 31 a and 31 b of the gas turbine 10via the high pressure air supply system so as to cool these hightemperature sections 31 a and 31 b. Thus, no thermal stress or thermalfatigue is excessively applied to the material of the high temperaturesections 31 a and 31 b of the gas turbine 10, so that the materialstrength can be kept at a preferable state.

[0338]FIG. 28 is a graph showing a comparison in a plant heat (thermal)efficiency between a gas turbine plant according to each embodiment ofthe present invention and the prior art. In the gas turbine plantaccording to each embodiment of the present invention, the high pressureair of the air compressor 8 is used as a heating source, and the fuel Fsupplied from the fuel section 12 to the gas turbine combustor 9 isheated by the heat exchange section 16, and thus, the quantity of heat(energy) of the fuel F is enhanced. By doing so, it is possible toimprove a plant heat efficiency by consumption of a small fuel F. Inparticular, in the case where the same temperature gas turbine drive gasis generated by a gas turbine plant according to each embodiment of thepresent invention and the prior art, the gas turbine plant according toeach embodiment of the present invention and the prior art makes itpossible to relatively reduce the consumption of the fuel F as comparedwith the prior art. Therefore, the plant heat efficiency can be improvedabout 0.5 to 1.0% as compared with the prior art.

[0339] It is to be noted that the present invention is not limited tothe described embodiments and many other changes, modifications andcombinations thereof will be made without departing from the scopes ofthe appended claims.

What is claimed is:
 1. A gas turbine plant comprising: an aircompressor; a gas turbine; a driven equipment, said air compressor, saidgas turbine and said driven equipment being operatively connected inseries; a gas turbine combustor arranged between the air compressor andthe gas turbine; a fuel system for supplying a fuel to the gas turbinecombustor; and a heat exchange section for heating the fuel from saidfuel system by means of a high pressure air as a heating source from theair compressor.
 2. A gas turbine plant according to claim 1, whereinsaid heat exchange section is housed in the air compressor.
 3. A gasturbine plant according to claim 1, wherein said heat exchange sectionis mounted to a casing of the air compressor.
 4. A gas turbine plantaccording to claim 3, wherein said heat exchange section mounted to thecasing of the air compressor has a structure that a fuel passage isformed by an outer cover covering an outer periphery of the casing, oneside of the fuel passage being provided with a fuel inlet and a fueloutlet and another side of the fuel passage is provided with aconnecting pipe.
 5. A gas turbine plant comprising: an air compressor; agas turbine; a driven equipment, said air compressor, said gas turbineand said driven equipment being operatively connected in series; a gasturbine combustor arranged between the air compressor and the gasturbine; a fuel system for supplying a fuel to the gas turbinecombustor; an extraction closed circuit system provided for said aircompressor; and a heat exchange section provided for said extractionclosed circuit system for heating the fuel supplied to the gas turbinecombustor from the fuel system.
 6. A gas turbine plant comprising: anair compressor; a gas turbine including an exhaust gas system; a drivenequipment, said air compressor, said gas turbine and said drivenequipment being operatively connected in series; a gas turbine combustorarranged between the air compressor and the gas turbine; a fuel systemfor supplying a fuel to the gas turbine combustor; and a heat exchangesection provided for said exhaust gas system of the gas turbine forheating the fuel supplied to the gas turbine combustor from the fuelsystem.
 7. A gas turbine plant comprising: an air compressor; a gasturbine including a high temperature section; a driven equipment, saidair compressor, said gas turbine and said driven equipment beingoperatively connected in series; a gas turbine combustor arrangedbetween the air compressor and the gas turbine; a fuel system forsupplying a fuel to the gas turbine combustor; a high pressure airsupply system operatively connected to the high temperature section ofthe gas turbine for supplying a high pressure air from the aircompressor thereto; a heat exchange section provided for the highpressure air supply system for heating the fuel supplied to the gasturbine combustor from the fuel system, the high pressure air after theheating being supplied to the high temperature section of the gasturbine as a cooling medium; and a high pressure air recovery system forrecovering the an overall quantity or part of the high pressure air tothe air compressor after cooling the high temperature section of the gasturbine.
 8. A gas turbine plant according to claim 7, wherein the highpressure air supply system is divided into a plurality of high pressureair supply sections in accordance with a magnitude of pressure loss ofthe high pressure air passing through the high temperature section ofthe gas turbine, said plurality of high pressure air supply sectionseach being provided with a flow distributing device.
 9. A gas turbineplant according to claim 8, wherein said flow distributing device iseither one of a flow control valve and an orifice.
 10. A gas turbineplant according to claim 8, wherein said high pressure air recoverysystem is divided into a plurality of high pressure air recoverysections so as to correspond to the divided plurality of high pressureair supply sections.
 11. A gas turbine plant comprising: an aircompressor; a gas turbine including a high temperature section; a drivenequipment, said air compressor, said gas turbine and said drivenequipment being operatively connected in series; a gas turbine combustorarranged between the air compressor and the gas turbine; a fuel systemfor supplying a fuel to the gas turbine combustor; a high pressure airsupply system operatively connected to the high temperature section ofthe gas turbine for supplying a high pressure air from the aircompressor thereto; and a heat exchange section provided for the highpressure air supply system for heating the fuel supplied to the gasturbine combustor from the fuel system, the high pressure air after theheating being supplied to the high temperature section of the gasturbine as a cooling medium and the high pressure air after cooling thehigh temperature section being joined with a gas turbine driving gas.12. A gas turbine plant according to claim 11, wherein the high pressureair supply system is divided into a plurality of high pressure airsupply sections in accordance with a magnitude of pressure loss of thehigh pressure air passing through the high temperature section of thegas turbine, said plurality of high pressure air supply sections eachbeing provided with a flow distributing device.
 13. A gas turbine plantaccording to claim 12, wherein said flow distributing device is eitherone of a flow control valve and an orifice.
 14. A gas turbine plantcomprising: an air compressor; a gas turbine including at least one hightemperature section; a driven equipment, said air compressor, said gasturbine and said driven equipment being operatively connected in series;a gas turbine combustor arranged between the air compressor and the gasturbine; a fuel system for supplying a fuel to the gas turbinecombustor; a high pressure air supply system operatively connected tothe high temperature section of the gas turbine for supplying a highpressure air from the air compressor thereto; a heat exchange sectionprovided for the high pressure air supply system for heating the fuelsupplied to the gas turbine combustor from the fuel system; a firstpressure rising compressor for rising a pressure of the high pressureair after heating the fuel and for supplying the high pressure air to atleast one of the high temperature sections of the gas turbine as acooling medium; a second pressure rising compressor which is bypassedfrom an outlet side of the first pressure rising compressor and rising apressure of the high pressure air after heating the fuel and forsupplying the high pressure air to at least one of other hightemperature sections of the gas turbine as a cooling medium; and a highpressure air recovery system for recovering an overall quantity or partof the high pressure air after cooling the high temperature sections ofthe gas turbine to the air compressor.
 15. A gas turbine plantcomprising: an air compressor; a gas turbine including a plurality ofhigh temperature sections; a driven equipment, said air compressor, saidgas turbine and said driven equipment being operatively connected inseries; a gas turbine combustor arranged between the air compressor andthe gas turbine; a fuel system for supplying a fuel to the gas turbinecombustor; a high pressure air supply system operatively connected tothe high temperature sections of the gas turbine for supplying a highpressure air from the air compressor thereto; a heat exchange sectionprovided for the high pressure air supply system for heating the fuelsupplied to the gas turbine combustor from the fuel system; a pluralityof pressure rising compressors for rising a pressure of the highpressure air after heating the fuel and for supplying the high pressureair to the high temperature sections, respectively, as a cooling medium;and a high pressure air recovery system for recovering an overallquantity or part of the high pressure air after cooling the hightemperature sections of the gas turbine to the air compressor.
 16. A gasturbine plant comprising: an air compressor; a gas turbine including aplurality of high temperature sections; a driven equipment, said aircompressor, said gas turbine and said driven equipment being operativelyconnected in series; a gas turbine combustor arranged between the aircompressor and the gas turbine; a fuel system for supplying a fuel tothe gas turbine combustor; a high pressure air supply system operativelyconnected to the high temperature sections of the gas turbine forsupplying a high pressure air from the air compressor thereto; a heatexchange section provided for the high pressure air supply system forheating the fuel supplied to the gas turbine combustor from the fuelsystem; a pressure rising compressor for rising a pressure of the highpressure air after heating the fuel and for supplying the high pressureair to the at least one high temperature section as a cooling medium,said high pressure air supply system being directly connected to atleast one of other high temperature sections so as to supply the highpressure air after heating the fuel as a cooling medium; and a pluralityof high pressure air recovery systems for recovering an overall quantityor part of the high pressure air after cooling the high temperaturesections of the gas turbine to the air compressor in accordance with theplurality of high temperature sections, respectively.
 17. A gas turbineplant comprising: an air compressor; a gas turbine including a pluralityof high temperature sections; a driven equipment, said air compressor,said gas turbine and said driven equipment being operatively connectedin series; a gas turbine combustor arranged between the air compressorand the gas turbine; a fuel system for supplying a fuel to the gasturbine combustor; a high pressure air supply system operativelyconnected to the high temperature sections of the gas turbine forsupplying a high pressure air from the air compressor thereto; a heatexchange section provided for the high pressure air supply system forheating the fuel supplied to the gas turbine combustor from the fuelsystem; a pressure rising compressor for rising a pressure of the highpressure air after heating the fuel and for supplying the high pressureair to the high temperature sections of the gas turbine as a coolingmedium; a high pressure air recovery system for recovering an overallquantity or part of the high pressure air after cooling at least one ofsaid high temperature sections of the gas turbine to the air compressor;and a cooling recovery system for recovering the overall quantity orpart of the high pressure air after cooling at least one of other hightemperature sections of the gas turbine to an inlet side of the heatexchange section.
 18. A gas turbine plant comprising: an air compressor;a gas turbine including a high temperature section; a driven equipment,said air compressor, said gas turbine and said driven equipment beingoperatively connected in series; a gas turbine combustor arrangedbetween the air compressor and the gas turbine; a fuel system forsupplying a fuel to the gas turbine combustor; and an air extractionclosed circuit system provided for said air compressor, said airextraction closed circuit system being provided with a heat exchangesection for heating the fuel from said fuel system and another heatexchange section for heating a heat utilizing device for heating amedium to be heated of the heat utilizing device.
 19. A gas turbineplant comprising: an air compressor; a gas turbine including an exhaustgas system and being combined with a steam turbine; a driven equipment,said air compressor, said gas turbine and said driven equipment beingoperatively connected in series; a gas turbine combustor arrangedbetween the air compressor and the gas turbine; a fuel system forsupplying a fuel to the gas turbine combustor; a heat exchange sectionprovided for the exhaust gas system of the gas turbine for heating afuel supplied from the fuel system to the gas turbine combustor; and aplurality of exhaust heat recovery heat exchange section provided forthe exhaust gas system of the gas turbine for heating a feed water ofthe steam turbine plant so as to generate a steam.
 20. A gas turbineplant comprising: an air compressor; a gas turbine including a hightemperature section; a driven equipment, said air compressor, said gasturbine and said driven equipment being operatively connected in series;a gas turbine combustor arranged between the air compressor and the gasturbine; a fuel system for supplying a fuel to the gas turbinecombustor; and an air extraction closed circuit system provided for saidair compressor, said air extraction closed circuit system being providedwith a heat exchange section for heating the fuel from said fuel systemto the gas turbine combustor, a valve opening control means fordetecting a fuel leak into the high pressure air by a fuel leakdetector, provided for the heat exchange section and for closing a fuelvalve of the fuel system when a detection signal exceeds a predeterminedvalue, and an alarm device for giving an alarm when the detection signalexceeds the predetermined value.
 21. A gas turbine plant comprising: anair compressor; a gas turbine; a driven equipment, said air compressor,said gas turbine and said driven equipment being operatively connectedin series; a gas turbine combustor arranged between the air compressorand the gas turbine; a fuel system for supplying a fuel to the gasturbine combustor; and a heat exchange section for heating the fuel fromsaid fuel system by means of a high pressure air as a heating sourcefrom the air compressor, said heat exchange section being divided into afirst heat exchange unit for heating an intermediate heating medium by ahigh temperature heating medium and a second heat exchange unit forheating the fuel by the thus heated intermediate heating medium.
 22. Agas turbine plant comprising: an air compressor; a gas turbine; a drivenequipment, said air compressor, said gas turbine and said drivenequipment being operatively connected in series; a gas turbine combustorarranged between the air compressor and the gas turbine; a fuel systemfor supplying a fuel to the gas turbine combustor; and a heat exchangesection for heating the fuel from said fuel system by means of a highpressure air as a heating source from the air compressor, said heatexchange section being divided into a high temperature chamber and a lowtemperature chamber and being provided with a heating pipe crossing thehigh temperature chamber and the low temperature chamber so that theheating pipe is heated by a high temperature heating medium in the hightemperature chamber and the fuel is heated in the low temperaturechamber.
 23. A gas turbine plant comprising: an air compressor includingan air discharging means; a gas turbine; a driven equipment, said aircompressor, said gas turbine and said driven equipment being operativelyconnected in series; a gas turbine combustor arranged between the aircompressor and the gas turbine; a fuel system for supplying a fuel tothe gas turbine combustor; a discharge air recovery system provided soas to bypass the air discharging system of the air compressor, said airdischarging means being provided with an air discharge valve to which isdisposed a valve opening control means which opens and closes the airdischarge valve in response to at least one signal of a rotational speedsignal of a gas turbine shaft and a power signal of the drivenequipment; and a heat exchange section provided for the discharge airrecovery system for heating the fuel supplied from the fuel system tothe gas turbine combustor.
 24. A gas turbine plant comprising: an aircompressor; a gas turbine including at least one high temperaturesection; a driven equipment, said air compressor, said gas turbine andsaid driven equipment being operatively connected in series; a gasturbine combustor arranged between the air compressor and the gasturbine; a fuel system for supplying a fuel to the gas turbinecombustor; a high pressure air supply system operatively connected tothe high temperature section of the gas turbine for supplying a highpressure air from the air compressor thereto; a heat exchange sectionprovided for the high pressure air supply system for heating the fuelsupplied to the gas turbine combustor from the fuel system; a pressurerising compressor for rising a pressure of the high pressure air afterheating the fuel and for supplying the high pressure air to at least oneof the high temperature sections of the gas turbine as a cooling medium,said pressure rising compressor being connected to a gas turbine shaft;and at least one high pressure air recovery system for recovering anoverall quantity or part of the high pressure air after cooling the atleast one of the high temperature sections of the gas turbine to the aircompressor.
 25. A gas turbine plant according to claim 24, wherein saidpressure rising compressor is directly connected to the gas turbineshaft.
 26. A gas turbine plant according to claim 24, wherein saidpressure rising compressor is connected to the gas turbine shaft througha power transmission mechanism.
 27. A gas turbine plant according toclaim 26, wherein said power transmission mechanism section is composedof either one of a gear mechanism and a torque converter mechanism.